Cord lock for venetian blinds



- J. c. BENNETT 2,786,551

March 26, 1957 CORD LOCK FOR VENETIAN BLINDS 2 Sheets-Sheet 1 Filed March 3 1951 4 Y r i 2 lllllllllll 14 1 E5 Illlllllllllll "Hm" I 3] 16d 4 22 [164% 28 Ell Lug I 16 INVENTOR. I 'rl4MEs C. BENNETT,

'b i aqwaav ATTOEMEY- March 26, 1957 J, c. BENNETT 2,786,551

CORD LOCK FOR VENETIAN BLINDS Filed March s, 1951 2 Sheets-Sheet 2 INVENTOR. 14445.; C BENNET A T TOQNE).

United States Patent t ice CORD'LOCK FOR VENETIAN BLINDS James C. Bennett, Inglewood, Calif assignor .to Anderson Die Casting & Engineering Co, Los Angeles, Calif., a corporation ofDelaware Application March.3, 1951,'Serial No. 213,746

9 Claims. (Cl. 188-64) This invention relatesto Venetian blinds and more particularly to cord locks for releasably holding such blinds in elevated positions.

It is an object of this invention to provide an improved cord Clock for automatically locking the lift cords of a Venetian blind upon release of the cords following manipulation thereof to raise or lower the blind.

It is another object of this invention to provide a cord lock of this character which is releasable responsive'to a pull on the lift cords in a direction toward the center of the blind. This arrangement makes it possib'le :to install blinds equipped with cord locks of the present invention, and to conveniently operate the cord locks, where walls or other obstructions located close to side edges of the blinds along which the lift cords extend, would prohibit or make undesirable the installation of blinds having cord locks requiring release by a pull on the cords toward such walls or obstructions.

It is a further object of this invention to provide a cord lock of such small dimensions, particularly as to height, that then-lock will be especially adapted for use in blinds .of the type wherein the tilt rail, the tilting mechanism, and the cord lock are housed and concealed in a hollow header. In blinds of this type, it 'is essential that the hollow or channelled header have minimum height or depth as well as small width to avoid taking up any appreciable window space as otherwise the header would objectionably obstruct the entrance of light aswell as the ingress and egress of air and prove unsightly.

Attempts to use cord locks heretofore available, in blinds having the tilt rail, tilting mechanism and cord lock housed and concealed in a hollow header, have re sulted in the use of headers of such dimensions that an objectionable amount of the window space 'has been c cupied. In most cases it has been diflicult, if not impossible, to provide for "free running of the lift cords through the header from the cord lock, as the cords are either extended at such angles :to avoid contact with the .parts in the header or are so disposed, that resultant friction interferes with free running of the cord and renders the operation thereof as well as the operation of the lock, inconvenient and unreliable.

It is therefore an important object of this invention to provide a cord lock which will eliminate the aforementioned objections and make it possible to employ a header or desirable small dimensions for housing and concealing the tilt rail, tilting mechanism and the .cord lock.

This invention possesses many other advantages and has other objects which may be made more easily apparent from a consideration of one embodiment of the invention. For this purpose there is shown a form in the drawings accompanying and forming part of the present specification. This form will. now be described in detail, illustrating the general principles of the invention; but it is to be understood that this detailed description is not to be taken in .a limiting sense, since the 2,786,551 P atented Mar. 2 1,957

scope of the invention -'is best defined by the appended claims.

Referring to thedrawings: I V

Fig. 1 'is a fragmentary front elevation, partly in secthan, of the upper portion of a Venetian 'blindenibody, ing the present invention;

Fig. 2 is .a top plan view of the blind; I

Figs. 3 and 4 are sectional views taken respectively on the lines .;3--3 and 4-4 of Fig. 1; 7

Fig. 5 is a sectional view of the cord lock, taken on the line 5--'5'ofFig. 6;

Fig. 6- is a vertical sectional view "taken on the "line 6-6 of Fig. 5;

Fig. -7 is a vertical sectional view taken on the "line 7-7 :of Fig. 5;

Fig.8 is a sectional view similar "to Fig. "5, showing how .the cord engages and moves the locking member upwardly;

Fig. '9 is a view similar to 'Fig. 8, showing the locking member in position to lock the cord.

In the accompanying drawings, numeral 1 0 designates a channelled header for a Venetian blind, which latter comprises slats 11, ladder tapes 12 supporting 'the'slats, a tilt .rail 13 supporting the .tapes, .a tilting device '14 for tilting the tilt rail, tilt cords 15 for operating the tilting device, lift cords .16 for raising and lowering the slats, and a ;cord lock '17 embodying the present invention.

As .here shown, the tilt rail 13, tilting device 14 and the cord lock 17 are housed and concealed in the header 10. The tilt cords 15 depend from the tilting device 14 through an opening 18 in the bottom of the header. IheJadder tapes -12 depend from the tilt ran '13 through openings 19 in the tilt rail. The threezdepending portions16a, 1 6 band 16c of the lift cords 16 extend through the twoopeni-ngs '19 and an opening 20 respectively in the bottom of the header, there being pulleys 2'1-and 22 in thejheader over which the lift cords extend .to form the depending portions 16a and 16b The lower ends of :thelift cord portions 16a and 16b are connected with the bottom rail ,(not shown) of the blind in .the usual manner. The cords 16 extend within the headerfrom the pulleys 21 and 22 in comparatively straight" runs 16d beneath the tilt rail to the cord .lock 17, from'whic'h latter the operating portions 16c :of .the liftlcord s ex tend downwardly so as to be accessible for raising' an lowering the blind.

The cord lock 17 includes a body member 24 mount- .ing a guide member in the formof a roller 25 over which the lift cords 16 are extended so as to form the depending operating portions 16c. Thisgbody member forms a :guideway W therethrough for the cords and is provided with flanges 26 by which it issecured to the upper surface of the bottom of the header 10 as by means of fastenings 27 as shown in Fig. 6. The .guideway registers with the opening 20 in the header.

In accordance with this invention means are provided for mounting a locking member or dog 28 on the body member 24 for sliding and pivotal movement relative thereto in order to releasably wedge and'lock the cords 16c against the roller 25 when moved upwardly and rocked on' its pivot, and to release the cords when rocked and moved downwardly toward its normal or lowermost position. The locking member or dog 28 and the roller .25 are positioned so that when the locking member is in its lowermost unlocked position, the cords may be pulled downwardly or allowed to run upwardly without contacting and operating the locking member, while raising or lowering the blind. In other words, as long as the cords are under tension while being manipulated, they may be moved freely without moving the locking member. However, when the lift cords are released bythe manipulator while the blind is elevated, the inherent resiliency and flexibility of the cords are such that the cords will spring or bow outwardly from the roller 25 and contact the locking member as indicated by the dotdash lines in Fig. 5. Thus, the weight of the blind causes the depending portions 16c of the cords to be pulled upwardly whereby the locking member is first moved upwardly toward the roller 25 and then swung on its pivotal axis so as to wedge and lock the cords against the roller. A comparatively short upward movement of the depending portions 160 of the cord takes place in actuating the locking member to lock the cords. The cords may be readily released by pulling downwardly thereon in a direction toward the center of the blind, the locking member moving downwardly away from the roller and into the cord-releasing position shown in Fig. 5.

As here shown, the body member 24 is formed of two opposed upstanding side walls 24a and 24b having the flanges 26 at their lower ends. The wall portion 24a (see Fig. 6) has an integral trunnion 29 on which the roller 25 is mounted so as to be disposed between the side walls in the guideway W. The wall 2412 has an opening 30 which receives the outer end of the trunnion 29. A cap screw 31 threaded into the trunnion secures the side walls in assembled relation. A spacer block 32 is formed integral with the lower portion of the side wall 24a below the roller 25 and abuts the other side wall 24b, there being a lug 33 on the block 32 engaging an opening 34 in the wall 24b.

An end member or wall 35, located between the side walls of the body member, is formed integrally with one side wall and abuts the other side wall, being secured thereto by a cap screw 36.

As here provided the locking member or dog 28 is formed of two similar sections 28a and 28b mounted side by side between the side walls 24a and 24b. A trunnion 37 on one of these sections, as section 28, is rotatably mounted in a recess 38 in the other section whereby said sections are connected for relative turning movement about the axis of said trunnion. The sections 28a and 28b are provided with trunnions 39 which are slidable and rotatable in similar, aligned slots 40 in the opposed side walls of the body member 24, said slots extending obliquely upwardly toward the roller 25. The trunnions 39 are located off center and provide an eccentric mounting for the locking member, there being serrations on teeth 41 on the sections of the locking memher for gripping the cord portions 16c.

Means are provided for limiting relative pivotal movement between the sections 28a and 28b, in the form of pin 42. on the section 28b and extending into a recess 44 in the section 28a, the recess being of greater diameter than the pin. This double dog locking means and the provision for limited relative pivotal movement between the sections thereof assures that the two lift cord portions 160 will be properly engaged and locked regardless of one of the cord portions being laterally offset from the other or otherwise misaligned.

Means are provided for controlling the slidable and pivotal movement of the locking member 28 so that the two sections 28a and 28b of the locking member will first slide upwardly as a unit, then will be turned on the pivotal axis thereof throughout the remainder of the sliding movement. As here shown, this means consists of a bearing surface 45 on the end wall 35 which surface is parallel with the slots 40 and adapted to be slidably engaged by similar fiat bearing surfaces 46 on the sections 28a and 28b of the locking member 28. The surfaces 46 extend above and below the pivotal axis (-trunnions 39) of the locking member 28 when the latter is in cord releasing position. The surface 45 on the end wall 35 also extends above and below the pivotal axis of the locking member when the latter is in cord releasing position, and terminates below the upper ends of the slots 40. Above the surface 45 the end wall 35 is formed with, a recess 47 which provides a shoulder 48. -The two sections 28a and 28b of the locking member 28 are provided at their upper ends with similar rounded and portions 49 which are adapted to extend into the recess 47 when the locking member is turned on its pivotal axis. As shown in Fig. 9, the shoulder 48 will contact the surfaces 46 on the locking sections 28a and 28b to limit movement thereof.

When the locking member 28 is in its lowermost cordreleasing position, as shown in Fig. 5, the cords may be manipulated in the usual manner to raise or lower the blind without actuating the locking member. The space between the roller 25 and the locking member is sufficient to permit the cords to be pulled downwardly or pulled upwardly by the weight of the blind, provided in both instances, the operator maintains the cords under tension. However, when the operator releases the cords 16c while the blind is elevated, the cords will spring or how outwardly between the roller 25 and the locking member 28 into contact with the teeth 41 on the locking member as indicated by the dot dash lines in Fig. 5. Thus, as the released cords ascend under the weight of the blind, the locking member is moved bodily upward in a path inclined toward the roller 25, and is restrained from pivotal movement by the surfaces 46 thereon sliding along the surface 45 on the end wall 35. As soon as the axis 39 of the locking member nears the upper end of the inclined surface 45, the locking member commences to turn on the pivotal axis thereof, as shown in Fig. 8. The recess 47 in the wall 35 permits of this pivotal movement of the locking member as the upward sliding thereof continues. This combined sliding and pivotal movement causes the locking member 28 to wedge and lock the cords against the roller 25, as shown in Fig. 9. The locking action of the locking member takes place during a comparatively short upward movement of the cords following release of the cords by the operator, and is therefore automatic, it being unnecessary for the operator to swing or guide the cords in any way in order to effect locking thereof to maintain the blind in the desired elevated position. However, in the event the cords become worn or lose resiliency such that they may fail to automatically engage and actuate the locking member, actuation of the locking member may readily be effected by the operator guiding the cords in their upward movement so as to engage and move the locking member into locking position.

When it is desired to release the cords, they are pulled downwardly in a direction toward the center of the blind, thereby moving the locking member downwardly and freeing the cords from engagement with the locking member, which latter then moves downwardly to its lowermost cord-releasing position as shown in Fig. 5.

The eccentric mounting of the locking member and the combined sliding and pivotal movement thereof as here provided, make it possible automatically to lock the lift cords with but a small amount of upward movement of the lift cords and locking member, thereby providing a cord lock or low height and also making it possible to employ a channelled or hollow header of desirable low height.

I claim:

1. A cord lock for the lift cords of a Venetian blind including: a body member; a guide member on said body member adapted to have the lift cords extend thereover and to depend therefrom; a cord locking member; and guiding means for said cord locking member slidable upwardly and downwardly on said body member in a path inclined from the vertical; said means supporting said cord locking member for sliding movement therewith as well as for swinging movement in a direction toward and away from the depending cords to occupy positions with respect to said guide member in which said cords are locked and released; said body member having a surface thereon inclined in correspondence to said path and engageable with said cord locking member during sliding mov m n o h la ter o res ra asa d akin m m e against tilting, and said surface terminating to permit said swinging movement of said cord (lockingmembel only atthe end of said path.

2. A cord lock for the lift cords of a Venetian blind including: a body member; a guide member on said body member adapted to have the' lift cords extend thereover and to dependh e m; sa d dy mem e having pposed walls provided with slots inclined from the vertical toward said guide member; a cord locking member; pivot pins in said slots mounting said locking member for sliding movement and for swinging movement about the axis of said pins toward and away from said guide member to positions for locking and releasing said cords; and a guiding member for said locking member disposed between said walls providing a surface inclined from the vertical in correspondence to the inclination of said slots; said surface terminating below' the upper ends of said slots and being disposed to engage said locking member, said surface restraining said locking member from tilting during sliding movement of the latter, and said surface terminated to permit the sliding movement of said looking member only at the end of said path.

3. In a cord lock for the lift cords of a Venetian blind; a body member; a cord guiding roller on said member; said body member having slots extended obliquely upwardly toward said roller; a cord locking dog having a toothed end; pivot pins slidable in said slots supporting said dog for swinging movement toward and away from said roller as well as for sliding movement toward and away from said roller; and a member on said body for controlling the swinging movement of said dog; said last named member having a surface opposed to an edge of said dog and inclined in correspondence with said slots; said surface terminating below the upper ends of said slots; said pins being movable in said slots to a point above said termination of said surface; said surface engaging said edge of said dog and restraining swinging movement of the dog while said pins are disposed below said termination of said surface, said pins when above said termination of said surface permitting said swinging movement of said dog.

4. In a cord lock for the lift cords of a Venetian blind; a body member; a cord guiding roller on said member; said body member having slots extended obliquely upwardly toward said roller; a cord locking dog having a toothed end; pivot pins slidable in said slots supporting said dog for swinging movement toward and away from 'said roller as well as for sliding movement toward and away from said roller; and a member on said body for controlling the swinging movement of said dog; said last named member having a surface opposed to an edge of the dog and inclined in correspondence with said slots; said surface terminating below the upper ends of said slots; said pins being movable in said slots to a point above said termination of said surface; said surface engaging said edge of said dog restraining swinging movement of the-dog while said pins are disposed below said termination of said surface and permitting swinging movement of the dog while said pins are disposed above said termination; said dog including relatively movable side by side sections; and interengaging elements on opposed surfaces of said sections to limit said relative movement.

5. In a cord lock for the lift cords of a Venetian blind; a body forming a guideway for the lift cords; said body having opposed side walls and an end wall between said side walls; a cord guide roller mounted between said side walls; said side walls having opposed slots therein extending obliquely upwardly toward said roller; said end wall having a surface extending from a point spaced below the lower ends of said slots to a point spaced below the upper ends of said slots; a cord locking member; pivot pins slidable in said slots supporting said locking member for swinging movement toward said roller; said lockingmember having an edge engageable with saidsurface .of said end wall to restrain swinging movement of said locking member during part of theupward sliding movementof said pins in said slot s;.said pins being disposed between the ends of .said locking member wherebysaid locking member is free to swing about said pins when said pins in sliding upwardly, reach positions adjacent and above the upper end of said surface on said end wall.

6. In acordlock for thelift cords of a Venetian blind; a body; a lift cord guide member mounted on said body; a lift cord locking member mounted on said body to swing toward andaway from said guide member as'well as to move bodily toward and away from said guide member to'positions for locking and releasing the lift cords; and a member on said body providing a pair of angularly related surfaces for controlling bodily and swinging move ment of said locking member toward said guide member responsive to the movement of said lift cords between said locking member and said guide member, said surfaces permitting tilting of said locking member only at the top of the movement of the locking member; one of said surfaces being disposed to engage an edge of said locking member during a portion of said bodily movement to restrain swinging movement of said locking member and to be disengaged by said edge upon further bodily movement of said locking member; the other of said surfaces being disposed to be engaged by said edge to limit the swinging movement of said locking member following said disengagement of said edge from said one surface.

7. In a cord lock for the lift cords of a Venetian blind; a body forming a guideway for the lift cords; said body having opposed side walls and an end wall therebetween; a cord guide roller mounted between said side walls; said side walls having opposed slots therein extending obliquely upwardly toward said roller; a cord locking member;

and pivot pins slidable in said slots supporting said cord locking member for swinging movement toward said roller as well as for bodily movement toward said roller to a position for locking said cords; said locking member being elongated, rounded at one end and pointed at the other end; said pins being mounted on said locking member between said ends; said end wall having a surface disposed to one side of said slots for engaging an edge of said locking member between said ends to restrain swinging movement of said locking member in a direction toward said roller; said surface on said end wall terminating below the upper ends of said slots; said end wall being relieved above said surface to define a recess for accommodating said rounded end when said locking member is swung towards said roller on said pins; said edge being disengageable from said surface upon swinging movement of said locking member when said pins reach a predetermined position in said slots.

8. In a cord lock for the lift cords of a Venetian blind; a body forming a guideway for the lift cords; said body having opposed side walls and an end wall therebetween; a cord guide roller mounted between said side walls; said side walls having opposed slots therein extending obliquely upwardly toward said roller; a cord locking member; pivot pins slidable in said slots supporting said cord locking member for swinging movement toward said roller as well as for bodily movement toward said roller to a position for locking said cords; said locking member being elongated and pointed at one end; said pins being mounted on said locking member between the ends thereof; said end wall having a surface disposed to one side of said slots for engaging an edge of said locking member to restrain swinging movement of said locking member in a direction toward said roller; said surface on said end wall terminating below the upper ends of said slots; said end wall being relieved above said surface to define a recess for accommodating the other end of said locking member when said locking member is swung towards said roller on said pins; said edge being disengageable from said surface upon swinging movement of said locking member when said pins reach a predetermined position in said slots; and a shoulder on said end wall engageable by said edge to limit swinging movement of said locking member toward said roller.

9. A cord lock for the lift cords of a Venetian blind including: a body member; a guide member on said body member adapted to have the lift cords extend thereover and depend therefrom; a cord locking member; said bodyrnember having opposed walls; said walls having slots therein; said cord locking member including a pair of relatively movable sections in side-by-side relation; a trunnion on one of said sections; the other section having a recess in which said trunnion is mounted; other trunnions on said sections aligned with said first named trunnion slidably and rotatably mounted in said slots, elements on said sections engageable to limit relative movement of said sections; said other trunnions providing for swinging movement of said sections toward said guide member; and portions on said sections and said body member respectively, cooperable for controlling said swinging movement of said sections.

References Cited in the file of this patent UNITED STATES PATENTS 400,546 Conklin Apr. 2, 1889 438,398 Bowers Oct. 14, 1890 1,804,811 Rosel May 12, 1931 1,865,935 Marshall et al. July 5, 1932 2,031,407 Campbell Feb. 18, 1936 2,087,865 Walker July 20, 1937 2,091,033 Dodge Aug. 24, 1937 2,198,187 Tolley et al. Apr. 23, 1940 

